Turbine bucket-wheel.



Patented Oct. 20, 1908. 2 SHEETS-SHEET 1.

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TURBINE BUCKET WHEEL.

APPLICATION FILED MAB..17, 1908 I UNITED STATES PATENT oFE oE.

WILLIAM L. R. EMMET, OF SUHENEUTAIJY, NEW YURK, ASSIGNO'R TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TURBINE BUCICET-YIIEEL.

Specification of Letters Patent.

Patented. Oct. 20, 1908.

Application filed March 17, 1908.. Serial No. 421,757.

To all :whom it may concern: 7 Be it known that I, WILLIAM'L. R. EM-

MET, a citizen of the United States, residingspecification.

- vention, Figure 1 is a miles a minute.

The resent invention relates to" bucket wheels or elastic fluid turbines and has for its object to improve their construction, particular reference being made to increasin their rigidity,'decreas1ng their weight an reducin the cost of manufacture. In t e accom anying drawings which illustrate one of t e embodiments of m inartial view in elevation. of a bucket whee Fig. 2 is a partial axial section thereof; Fi 3 is a artial section taken on line 3-3 0 Fig. 4; ig. 4 is an enlarged detail view showing the bucket securing means; Fi 5 is a perspective view of a bucket; and ig. 6 a perspective view of a s ace block.

n order to full a preciate the conditions underwhich the [in liet wheels of my invention operate, a general statement as an exam le will be beneficial. The wheel shown is a out twelve feet six inches in diameter on the pitch line of the buckets and wei he between'five and six thousand oun s, the weight varying somewhat with t e length of the buckets. The buckets when in o eration travel through space at about four undred and sixty feet With buckets of moderate size in such a wheel there-is a force due to centrifugal action of about six hundred ounds per bucket tending to separate it mm the wheel. This force increases with an increase in weight of each bucket and also with anincreased shaft speed. The buckets rotate between stationar arts, such for example as the nozzle an the intermediate buckets arranged in a row between the rows of wheel buckets. The clearance between the relatively rotating parts varies with different conditions, .06 to .12 not being unusual. The figures above mentioned have "beengiven merely as examples and are not to per second, or overfive that serve to brace the flat disks 4 located on opposite sides thereof. I prefer to use separate arms as shown rather than a solid member in order to decrease the weight of the wheel as much as ossible. The disks 4 are made of commercial rolled plate of the desired thickness. These plates are roughly sheared to size and are then put in a boring mill and bored to the required dimension, and the periphery turned to thedesired diameter. The inner faces 5 of the disks are made flat, while the outer faces 6 are turned off so that'the peripheral portions are somewhat thinner than the portions adjacent the hub. Between the annular flange 2 and each of the disks is a shoulder 7 formed on the flange and entering a corresponding recess in the disk. I prefer to form the shoulder on the flange rather than on the disk because this arrangement does not require the turning ofi of any considerable amount of metal on the disks and hence the latter can be made thinner than would be the case if the shoulder Was formed on the disk and seated in a groove formed in the annular flange 2. These disks are attached to the flange and arms by axially-extending rivets 8. By using shoulders 7 as described, the shearing strains on the rivet-s are decreased, and the strains due to centrifugal force are transmitted directly to the hub.

The hub is provided with a bore 9 of'suitable diameter and also with key-ways or slots 10 to receive the keys that secure the wheel on the main shaft. The wheels are usually forced on the shaft under considerable pressure and in order to remove them from. the shaft and also to handle them by a crane when removed it is necessary to provide means whereby they can be readily handled without injury. To this end the flange 2 is rovided with screw-threaded openin s l1, lbur being shown, to receive eye-bolts or other devices to which the books on the crane can be attached or to which other means can be attached for seating the wheel on the shaft or ulling it ofl. Registering with the screw-t needed '0 cn-ings are holes 12 in the plates of slightly arger diameter so that the strains due to the use of the eyebolts are transmitted directl to the hub. rather than to the disks. If tie holes in the disk were screw-threaded and the eye-bolts by accident were not firmly seater flange then when force was exerted on the in the eye-bolts they mi ht so strain the rivets as to weaken the whee as a whole which thereafter would be a source of danger.

At a point near the periphery of each disk and on the inner face a rectangular groove 13 is provided in which is seated an annular spacing member 14. This member is rovided with a series of openings 15 to a mit .steam to the interior of the wheel so th t the internal temperature will be the same, 0 substantially the same, as the external, and so a their peripheries due to any cause a number of axially-extending rivets. 17 are provided. It is to be noted that these rivets are located inside of the member 14 where they are out of the path of the moving steam and hence do not offer any resistance to-rotation. found in actual practice that it sometimes happens that a workman in heading over these rivets will strain the disks in such a manner that the part between the member 14- -and the flange and arms will be slightly dished or concaved, which throws the ets sli htly out of line.

buck- To obviate this, rectangu ar blocks 18 are provided through which the riyets pass. These blocks may. e of any suitable sha *e, and should be long enou h to prevent t e wheels from buckling or dis ing, as above described, when tb erivets 17 are headed.

Attached to the irmer face of each (11SK1S a steel base or back 19 containing a dove-tailed groove 20 to receive the dove-tailed ends 21 of the buckets 22. The buckets rated from each other by space The bases are secured to the inner faces of the are sepadisks by axially-extending rivets 24. In or- .der to reduce'theshearing strains on these rivets an annular roove 25 is turned in the inner face of each lsk, which groove is of rectangular cross-section and receives an annular shoulder or pro'ection formed on the base;

19 of each row of uckets. I prefer to form the shoulder. 26 on the base rather than on the disk because it decreases the amount of machine work and permits me to use ,disks that are thinner in the rough state than would bethe case if the shoulders were formed thereon. The basesfor the buckets as clearly shown in Fi 3.

are made up in segments of suitable length, By reasonof this construction I am a le to mount them in place without difiiculty and also to repair the wheel in case the buckets in one segment are injured or are defective, due to anv cause.

buckets,

I'have blocks 23.

The outer] ends of the buckets are providedhave to be of a width sufficient to properly turn the steam as it passes from one row of buckets to the other. The shape of these buckets is very similar to that of the wheel but their position is reversed in order to reverse the direction of the steam flow. In order to make the wheels as stiff as possible against deflection in an axial direction at or near the periphery they should be separatedas much as possible. This separation in a wheel havin two rows of buckets as shown is limited by 518 width of the intermediate buckets. It is undesirable to make the width of the intermediate buckets unduly rest for the reason that it increases the osses in the turbine due to friction, and also because it increases the overall length of the machine, the latter having a direct bearing on the cost of construction. I obtain-the greatest separation possible between the isks without, however, increasing the overalldimensions .of the turbine b mounting the bucket bases on the innerdices of the disks, as'best shown in Fig. 4. By reason of this construction I am able to, provide a wheel that is exceedin ly ri id while at the same time it is not mar le unduly heavy considering the amount of work it has to form. It is to be noted that the outer faces of the disksare has the advantage of losses due to t-he movement ofthe wheel on a bodyof steam ore or'less dense. By

using steel for the arts as described the ex pansion and contr ,tion of the parts under temperature chang s will be equal, thus preventing one part w rking loose from another part or parts. Z:

In accordance 'th the provisions of the patent statutes, I lave described the principle of operation f my invention, together with the a parat s which I now consider to re resent t I esire to have i understood that the apparatus shown is on y illustrative, and that the invention can be. armed out b other means.

'What I claimnewand esire to secure by Letters Patent of the United States, is,v

1. In a bucket. heel, the combination of a hub having an tached to oppositeisides of the ange, a row of'radial buckets or each disk, aseparate base for each row o buckets that is attached tothe inner face of its sup orting disk, and means for unitingthe dis to reduce the tendency to distortion.

2. In a bucket wheel, the combination of e bes embodiment thereof; but

perfectly smooth which decreasing the rotation annular flan e, disks. at- L faces of the disks,a shoulderv between each base and its disk to transmit strains from the former to the latter, and axially-extending means that clamp the bases to the disks.

3. In a bucket wheel, the combination of a hub having an annularflange, disks attached to opposite sides thereof, a row of buckets for each disk, bases for the buckets which are attached to the inner faces of the disks, an annular perforated member which separates the disks by a fixed distance near their eripheries, axially-extendingdevices for he ding the disks against said member, and means preventing the said devices from distorting the disks in the course of manufac- 'ture.

4. In a bucket wheel, the combination of a hub having an annular flange, radial arms attached thereto which form spacers, disks located on opposite sides of the flange and arms, a shoulder between the flange and each disk to transmit strains from the latter to the former, means clamping the disks to the flange and arms, a row of radial buckets for each disk, a base for each row of buckets that engages the inner fa cc of the disk, an annular shoulder between each base and the inner face of the disk to transmit strains from the former to the 'latter, means clamping each base to the inner face of the disk, and means for holding the disks at a fixed distance apart near their'peripheries. I

5. In a bucket wheel, the combination of a cast steel hub having an annular flange and arms radiating therefrom, rolled steel plates of disk form attached to opposite sides of the flange and arms, -rivets which pass through the flange, arms and disks to unite them,

shoulders between the disks and flange to transmit strainsfrom the former tothe latter and reduce shearing strains on the rivets, a row of radial buckets for each disk, separate steel bases in which the inner ends of each row of buckets are anchored, rivets for securing each'baseto the inner face of its supportin disk, a shoulder between each base and t e inner face of each disk to reduce the shearing strains on the rivets, and means separate fromthe bases for uniting the disks near their peripheries.

6. In a bucket Wheel, the combination of a hub having an annular flange and arms extending radially therefrom, annular shoulders on o posite sides of the flange, plates inade in t e form of disks located on opposite sides of the flange and rooved on their inner faces to receive ann ar shoulders on the' flange and bucket bases, the said disks ings therein to receive eve-bolts, disks attached to the sides of the hub member which are provided with openings registering with those in said member but of greater diameter, and buckets carried by each of the disks.

In witness whereof, I have hereunto set my hand this 10th day of March, 1908.

VVILLIAM L. R. EMMET.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. I 

